The present invention is directed to a stator used in an electrical motor or generator, an electrical motor or generator using such stator by combining a rotor with the stator, and method of manufacturing such stator. The invention is particularly useful for radial air gap motors or generators, but may have applications to other configurations, such as axial air gap motors or generators, or the like. The stator may surround the rotor or may be surrounded by the rotor. The resulting electrical motor or electrical generator may use a stator, according to an embodiment of the invention, in combination with a permanent magnet rotor, an induction rotor, a switched reluctance rotor, a DC brushed rotor, or the like, to form any type of rotating electrical device. While illustrated for use as a stator, certain aspects of the invention may be useful in making a rotor for an electrical motor or electrical generator.
Electrical motors and generators include a stator and rotor. The stator may be the armature and the rotor may be the electromagnetic field, or vice versa. One common form of motor is a radial air gap motor having an outer stator and a rotor inside of the stator, or vice versa. The stator is typically constructed of iron-based laminations that form the yoke and teeth as one piece. The tooth may be wider at the stator-rotor air gap than the main tooth body in order to better accumulate and focus the electromagnetic flux. The result may be very close spacing between adjacent teeth at the air gap.
Electrical conductors, such as insulated copper wires, are installed in slots between and encircling the teeth. In one common form of the stator, the conductors are installed by inserting the conductors through the spacing between the teeth. Because of the narrow opening between the teeth at the air gap, it is difficult to achieve precision in the final placement of the windings in the slots resulting in non-uniform winding layers. This leaves available winding space that is not occupied by the winding, which results in a finished device that achieves less than potential performance.